The present invention relates to locking devices, and more particularly relates to an apparatus for locking the doors of a trailer.
Large enclosed containers for trailers are often used with tractor trucks, railroad flat cars, barges, ships, and the like as a common mode of cargo movement. Large portions of commercial goods are transported in such containers. These goods may range from inexpensive perishables, such as vegetables, to expensive, fragile electronic devices, such as computers. The container itself may be handled by several intermediate transport companies and may be borne by several different vehicles before the goods themselves reach their final destination. For instance, the container may be first borne aboard a tractor trailer, then stacked on an inland waterway barge, then stacked in the hold of an ocean-going ship, later loaded on a railroad flat car, and finally loaded again on a tractor trailer for transport to a local warehouse or store.
The containers themselves often have rear or side doors for access, which are built in accordance with a relatively common standard. These doors normally open outward, and contain large rotating vertical securing rods that are affixed to the doors and can be used to latch and secure the doors in a substantially closed position. One or more of these vertical rods are normally affixed to each door in aligned sockets to permit rod rotation. These vertical rods are normally mounted parallel to one another, and near the edges of the doors where the doors abut together and overlap when in the closed position.
When the rods are rotated to a xe2x80x9cclosedxe2x80x9d position, cam pins near the upper and/or lower ends of the vertical rods latch within and against open box-like receptacles or housings mounted to the top and/or bottom frame edges of the container so that the doors may be tightly closed. Handles on the rods may be pulled upward from their normal positions and then used to rotate the rods. Therefore, when the doors are closed, an operator may rotate the rods to clasp the doors down tightly, lifting the handles when the rods are almost in their locked position and dropping the handles into latches in the face of the trailer door. This latching feature is meant to prevent the vertical rods from rotating once the doors are tightly closed. Padlocks or other similar locking devices are often used to lock these vertical rods into closed position.
Unfortunately, theft has become a major problem with such containers because of the manner in which they are used. Such containers are frequently left unattended for varying periods of time in storage facilities, or on railroad flat cars during transportation from one site to another. Thieves can easily break open the container doors and gain access to the goods inside by using pry bars, hammers, saws and other similar tools to break the locks on the vertical rods, thereby enabling the vertical rods to be pivoted to their open position, and consequently allowing the doors to be opened.
Various devices have been developed in an attempt to make it more difficult to break into such containers. Many of these devices consist of bars or rods that stretch across the doors of the container and lock into place, thereby blocking the doors and keeping them from opening. Some devices actually wrap around at least two of the vertical securing rods, thereby preventing the doors and their respective securing rods from separating. Most of these devices are expensive, cumbersome and difficult to manufacture and use. Furthermore, many of these devices still allow opportunities for thieves to circumvent them and break into the containers.
There is identified, therefore, a need for an improved locking device for the doors of trailers and other storage containers that overcomes disadvantages, shortcomings, or limitations of known locking devices for the doors of trailers and other storage containers.
An aspect of the invention is to provide an apparatus for locking the doors of a trailer, the doors having at least two securing rods for securing the door to the frame of the trailer, and the securing rods each including at least one cam pin attached near an end of the securing rod and the frame including one cam pin housing for cooperation with at least one of the cam pins. The apparatus includes a first tubular member, and a second tubular member structured and arranged to be received within the first tubular member, wherein the first and second tubular members each include means for engaging the cam pins to substantially prevent movement of the securing rods.
Another aspect of the present invention is to provide a trailer door assembly including at least two securing rods for securing the door assembly to a frame of a trailer, at least one cam pin attached near an end of at least one of the securing rods, at least one cam pin housing for cooperation with at least one of the cam pins, a first tubular member, and a second tubular member structured and arranged to be received within the first tubular member, wherein the first and second tubular members each include means for engaging the cam pins to substantially prevent movement of the securing rods.
A further aspect of the present invention is to provide a method of locking the doors of a trailer, the doors including at least two securing rods for securing the doors to a frame of the trailer, the securing rods each including at least one cam pin attached near an end of a securing rod, and the frame including at least one cam pin housing for cooperation with at least one of the cam pins. The method includes providing a locking apparatus, wherein the locking apparatus includes a first tubular member, a second tubular member structured and arranged to be received within the first tubular member, and wherein the first and second tubular members each include an L-shaped assembly comprising a base plate and a retaining plate extending generally outward from the base plate for engaging the cam pins to substantially prevent movement of the securing rods, placing the first and second tubular members between at least two of the securing rods in a substantially perpendicular position with respect to the securing rods, slidably positioning the first tubular member within the second tubular member so that each retaining plate substantially fills a gap between the cam pin and the wall of the cam pin housing, thereby preventing the cam pin from being removed from the cam pin housing, and securing the second tubular member within the first tubular member in a substantially locked position.
These and other aspects of the present invention will be more apparent from the following description.